These patents disclose hoist machines which can be mounted onto motor vehicles; they are provided with platforms or nacelles suitable for carrying persons or differing loads and which can be raised to prefixed heights of a maximum limit, for the different machines, varying from 20 m to 50 m.
These machines comprise three or four stages of acticulated levers which are activated by hydraulic cylinders. They are mounted on platforms which can be rotated more than 360.degree. around a vertical axis and are able to take the terminal nacelle to considerable heights thus allowing various kinds of work to be carried out. They are structurally stable, while the aerial nacelle is able to take up prominent overhang positions with respect to the base of the machine and can, for example, be positioned in space so as to be brought near to points on buildings and aerial electric lines which cannot be reached by other means. Thanks to their characteristic versatility, these machines have found use to a vast extent world wide. Prior Art machines, mounted on suitable motor vehicles, also when they are completely retracted, i.e. in the rest position with respect to the base platform, and the support motor vehicle, require a space that is very wide to make them suitable for work to be carried out at considerable heights. They cannot be used in environments defined by walls, such as, for example, exhibition halls, museums and the like.